In XX century we used to say that some perfect entrepreneur should mix and combine leadership and management skills to be 100% successful...is it still true on XXI century with our global challenge?
Even more so in a global economy. Both skill-sets are required in varying percentages, depending on what's going on in the business. Effective leadership is about inspiring and instilling confidence and "followership" in your staff, and demonstrating strength of character, conviction, and stability to customers. "Managing" is the set of skills needed to competently run the business. You have to have both, in good measure, to succeed.
Why would that not be the case? The answer is Yes. always has been and always will be.
There's a functional difference in leading an organization and leading (managing) a team operationally. As a Founder, usually by necessity, you will have a greater chance of success in your venture if you can excel at a 50/50 split of strengths for both in the early days.
Without the ability to communicate your vision and build the team you need to launch your venture, you won't attract a team. Once you have them, you've got to execute which requires significant management skills with people and project management to produce and deliver your product or service.
As your organization and your team grows, it's important to really self-assess/get feedback on where your true strength lies - leading or managing. If you are strongest in the leadership role - narrow your lens and channel your energy in growing that strength for the good of your company. Partner or staff up with strong managers who live and breathe your people, systems, products/services, etc. If you're strongest at management - partner up with a demonstrated leader who shares your VISION and ultimate goal(s).
Seth Godin had a great video a bit back that got into the heart of this: http://youtu.be/Xx2SV2bYSfU
The thing that makes me curious about your question is how it connects to your work. Do you feel that if you can't bring 100% you won't be able to compete in a "global" marketplace?
I don't think leadership and management will ever be mutually exclusive.
It's a battle of semantics. A manager has subordinates, a leader has followers. Since following is a voluntary action, a manager would have to give up authoritative control.
Still, employees can choose whether to follow you, or just acknowledge your orders.
Management skills are what identify that baseline of performance and use it to maximum efficiency. Leadership skills provide motivation so that baseline is increased.
Without a combination of these skills, you're missing out on the full potential of your team.
I would argue that being a "managing leader" is more important than ever to develop a successful team and business.